Meckle's Diverticulum
Diagnostic finding of meckel's scan
areas of heterotopic gastric mucosa present
What is an indication for mesenteric arteriography for meckel's diveritculum and what is found on a positive test?
○ Indication: if GI bleed is brisk enough to require transfusion and hasn't been identified through other modalities ○ Dx Findings: anomalous superior mesenteric artery branch feeding the diverticulum ■ Active contrast extravasation may be seen in pts with ongoing hemorrhage
5 complications of meckel's diverticulum?
● 1) Bleeding: ○ MC in young children: occurs when HCl is secreted from heterotopic gastric mucosa → this causes ulcers of adjacent ileal mucosa → bleeding ● 2) Obstruction ○ Caused by intussusception of the diverticulum (MC in children) ● 3) Diverticulitis ● 4) Perforation can lead to peritonitis ● 5) Tumors
How far from ileocecal valve is meckel's diverticulum located?
2 feet
What is meckels diverticulum most commonly confused with? How is it differentiated?
Acute appendicitis Clinically identical, diagnosed by normal appendix on exploration
What can make meckel's diverticulum hard to diagnose?
Clinical features (sxs, labs, exam, imaging) are nonspecific
Secondary prevention of meckels diverticulum
Currently no factors specifically reduce risk of surgical complications: no established preventative actions
Pathophysiology of Meckel's Diverticulum
incomplete obliteration of vitelline duct → forming a true diverticulum of the small bowel
Vitelline duct
long narrow tube that joins yolk sac to midgut lumen in developing fetus
50% of Meckel's diverticula also contain heterotropic tissues from what two organs?
stomach, pancreas, or both
2 types of mucosa lining a bleeding meckel's diveritculum
○ 1. Native intestinal mucosa ○ 2. Heterotopic mucosa (tissue other than intestinal mucosa)
Suspicion for Meckel's Diverticulum in 1) Adults 2) children as source for GI bleed is increased if:
○ Children <10 yo with painless GI bleed without s/sxs of gastroenteritis or IBD ○ Adults <40 yo with GI bleed w/ no source identified with endoscopy and radiographic eval (CT, colonoscopy, etc.)
Suspicion of Meckel's Diverticulum as source of SBO is increased for:
○ Children with SBO sxs who have recurrent intussusception following successful reduction
Symptoms of GI bleed in children and adults
○ Children: dark red or maroon stools ○ Adults: melena (attributable to slower colonic transit time)
3 Major symptoms of meckel's diverticulum if not asymptomatic
○ GI bleed (MC in children) ○ SBO (MC in adults) ○ Acute abdominal complaints =abdominal tenderness and distension associated with inflammation
7 Differential diagnoses of meckel's diverticulum
● Acute appendicitis ○ RLQ acute abdominal pain; associated with fever, anorexia, N/V ● Intussusception ○ MC in infants 5-7 months of age, vomiting, lethargy ● Infectious colitis ○ Diarrhea often present, hx of sick contacts, travel to endemic areas ● Colonic diverticulitis ○ Adults >40yo, LLQ pain, fever, malaise, leukocytosis ● Crohn's disease ○ RLQ pain, bloody diarrhea less common, weight loss ● Ulcerative Colitis ○ Bloody diarrhea more common, RLQ or LLQ pain, fecal urgency ● IBS ○ Non-specific pain, bloating, defecation issue
5 "Rules of 2's" of Meckel's diverticulum
● Occurs in approximately 2% of the population ○ Probably no familial predisposition ● Males > Females (2:1) ● Located within 2 feet from the ileocecal valve ● 2% of patients develop a complication in their lives, typically before age 2 ● A Meckel's diverticulum that bleeds is usually lined by 2 different types of mucosa
Who most commonly develops complications from meckel's diverticulum?
Risk of complications overall is higher in children: remember the "Rule of Twos" ○ 2% of pts develop a complication in their lifetime, typically before the age of 2 ● Males are 2-3x more likely than females to have complications
Surgical treatment for symptomatic meckels diverticulum
Surgical excision: simple diverticulectomy (excision of diverticulum at its base) or segmental small bowel resection ○ Endoscopic resection has been used for inverted Meckel's diverticulum ○ Bleeding: simple diverticulectomy and segmental small bowel resection are both effective ■ Adjunct blood transfusion if too much blood loss ○ Obstruction: surgical excision and lysis of adhesions ○ Adjunctive antibiotic therapy: Cefotaxime + Clindamycin or Metronidazole ■ Given preoperatively and for 24 hours postoperativel
What is the most common congenital anomaly of the GI tract?
Meckel's diverticulus
true diverticulum vs false diverticulum
1. True = all three mucosal layers (Mucosa (LP + MI) , Submucosal, Muscularis Externa) -> Congenital - Meckel's 2. False = Only mucosa and submucosa outpouch -> acquired (vasa recta perforation of muscularis externa)
What kind of scan is Meckel's scan and what is its indication?
(Nuclear medicine scan) ○ Indication: hemodynamically stable patients with intermittent or less severe GI bleed whom suspicion is high
4 Risk factors for developing SYMPTOMS from Meckel's diverticulum
1 Age <50 yo 2 Male sex 3 Diverticulum length > 2 cm 4 Presence of heterotopic/histologically abnormal tissue (ex: if the diverticulum secretes HCl because it has gastric cells)
3 potential diagnostic tests for Meckel's diverticulum
1 Mesenteric arteriography 2 Meckel's scan 3 Abdominopelvic CT (Least diagnostic)
If abdominopelvic CT identifies a potential meckel's diverticulum, what must be done to confirm?
Mesenteric arteriography or meckel's scan
What determines treatment of meckels diverticulum?
Presence of symptoms and age: ○ Asymptomatic + incidental finding of Meckel's diverticulum: resection is controversial ○ Children & adults + incidental finding of Meckel's diverticulum: elective resection not suggested ○ Meckel's diverticulum identified during abdominal exploration ■ Resection suggested for: ● Most children up to young adulthood that are healthy ● Healthy young adults <50yo + palpable abnormality or diverticulum >2cm ■ Resection not recommended for: ● >50yo unless there is a palpable abnormality with the diverticulum